Heaters intended for use with particulate fuel are known, being taught for example in U.S. Pat. Nos. 1,614,314 to Murray et al., and 1,812,080 to Chapman, but have not solved with complete success the problems inherent in the nature of these fuels, their lack of uniformity and practical size, the frequent presence of non-gaseous products of combustion, and the need to maintain an effective ignition locale for maintaining combustion. Starting operation of such burners is also sometimes troublesome.